ABSTRACT Tobacco use remains the number one cause of premature death and morbidity in the United States, and tobacco-related diseases account for 24% of all VA healthcare costs. The VA has been a leader in addressing tobacco use, having implemented annual tobacco screening and made pharmacotherapy readily available. However, one of the most cost-effective services - telephone quit lines - remain highly underused. Few Veterans enroll in telephone counseling to help them quit smoking, and among Veterans who begin telephone counseling, few complete a full course. The advent of electronic health records (EHRs) has enabled new strategies for ensuring that patients receive preventive services. These methods can reduce provider burden and close gaps in systems of care. Our research team has conducted numerous studies using EHRs to identify smokers and proactively reach out to coordinate telephone tobacco treatment. While we have successfully implemented this approach, the overall enrollment rates for counseling remain low and the majority of smokers complete only one counseling session. Therefore, we propose to test novel mHealth strategies for promoting enrollment in and adherence to telephone counseling. The Specific Aims are to: 1) Conduct a sequentially randomized trail to estimate the effectiveness of text messaging for increasing enrollment in and adherence to telephone tobacco treatment, 2) Compare rates of tobacco cessation between patients who received and did not receive text messaging during treatment, and 3) Evaluate patient experiences with these interventions. Using the VA EHR, we will identify N=3,600 smokers at three VA sites. All identified smokers will be mailed an introductory packet with information about the study. Patients who do not opt out will first be randomized to standard telephone outreach for counseling or to receive 8 educational texts to counter barriers of participating in counseling prior to telephone outreach. Patients who enroll in tobacco treatment will then be randomized to receive standard telephone counseling or to also receive appointment reminders and supportive texts throughout the 8-week counseling period. We hypothesize that these approaches will increase the rate of enrollment in telephone tobacco cessation and 12-month biochemically validated abstinence (primary outcomes) over standard telephone counseling approaches. We will also assess patient experiences with each texting protocol. Our overarching goal is to investigative innovative mHealth strategies for increasing Veteran use of telephone-based tobacco cessation counseling and to improve quit rates. This research, exploring both population-based outreach and text messaging, advances multiple goals set forth by the VA?s Blueprint for Excellence. Results will have direct implications to inform decision-making and population-based care models for tobacco treatment.